dzywicki

I have a 98 Cherokee that just started having a no crank scenario. I initially thought it was the starter and I had a lifetime warranty from Napa so removed and replaced that. It's 15 minutes out and 15 minutes in so not much lost there. I checked all fuses in the PDC and passenger side fuse panel and swapped the relays and all are good. Still get a no crank. I put the headlights on and tried to crank. No dimming at all and no clicking so power is definitely not getting to the solenoid. I checked power at the starter relay and it was getting the right readings (I'll double check from the thread I was reading), it was late and dark and I did it quickly. Reverse lights work fine.

Next steps:

1. Hook up starter button. Connect one lead to battery + and other end to small terminal on starter.
2. Bypass NSS by jumping pin 7&8 on the harness side connector

My question is on bypassing the NSS. There are plenty of threads and youtube videos. I did attempt it last night without luck but it was late and dark and it didn't do anything. When doing the bypass for testing, does the harness side need to be connected back to the NSS side or can it be jumped and left unconnected?

From what I am seeing, I'm guessing it's the NSS but want to verify by bypassing it first.

Saudade

Jumped and left unconnected for testing. Just be aware that you can then start it while in gear so make sure you're in park/neutral.

The starter relay on the coil side grounds through the NSS. The jumper merely bypasses this connection. The B+ for the coil side comes from the ignition key in the Start position. So once you turn the key to Start, the relay should energize (click) and then send 12v to the starter solenoid and the starter should crank.

dzywicki

Makes sense. Thank you for verifying the specifics. I am hoping it's just the NSS. Will post back this evening after I'm done with work and can troubleshoot more. Found my push button starter tester too so good to go for testing.

Saudade

You can test the NSS using an ohm meter or a continuity light. Disconnect the harness and use pins 7 & 8 on the NSS side. You should get continuity when in Park/Neutral.

dzywicki

Did some testing and eliminated the NSS. Bypass test didn't do anything. I put a multimeter on pins 7 & 8 and it showed continuity in P and N. Did not show continuity in other gears. I put a remote push button starter between the battery + and solenoid and it started right up. At this point, I am thinking it's the ignition switch. Had to troubleshoot my wifes Jeep and the blowing of the O2 sensor fuse so didn't complete all the diagnosis that I wanted to. Ignition switch replacement looks to be pretty simple. IIRC I had replaced the lock cylinder when I got the Jeep in 2018. The fun of old Jeeps. Will probably just install a push button bypass so the Jeep can be driven until I replace the ignition switch.

Saudade

You can pull the starter relay in the PDC and test for 12v at Pin 13 when the key is turned to START. If you get 12v, the issue lies elsewhere. If not, check Fuse 19 in the junction block again Again, you should have 12v when the key is turned to START. If not, unless there's a break in the wire somewhere, it's likely the ignition switch.

While you have the relay out, check Pin 10 for 12v/ This should always have 12v regardless of key position. If not, check Fuse 10 in the PDC.

dzywicki

That is my next check. I ordered a push button starter, should be here tomorrow. If it starts by providing power to the input for the starter relay, I'll just go push button and send it. I also ordered an ignition switch. I'll tear it down tomorrow and see if there is a problem there. Seems pretty simple to get power from the ignition switch to the starter relay one way or another.

dzywicki

Had a break between meetings and a spare relay. I verified that there is no voltage to pin 85 when ignition is on start. Also verified that it will start instantly when closing the connection at the starter relay. So definitely either the ignition swatch or something between the switch and the relay. I took a short clip. Installing the push button starter should be pretty easy.

dzywicki

I found that I have a copy of the FSM and found the wiring for the starter circuit. Attaching for future reference. I am really curious as to what is actually wrong with the ignition switch now. When I turn the key to start, the radio display goes off like it is supposed to (I verified that my 99 does the same thing). The headlights do not dim. I have to find my safety torx bits so I can remove the ignition switch. From the looks of the diagram, a push button starter should operate exactly as the ignition switch and not start it unless it's in P or N. Once I take the column cover off, I'll have to check continuity between the switch and the relay. The diagram shows it as a straight run. Soit's either that wire or the sitch is bad fr the start position.

dzywicki

And putting this on a broken metal piece in the ignition pin here for reference. This has got to be the problem I am having.

Saudade

That's not the right diagram for the '99 and it's also for right hand drive. Looks like one from '94-'96. The PDC is arranged differently and many of the connector pins are also labeled differently.

Go to Cruiser's site and get the 1999 FSM from the Tech manuals section.

https://cruiser54.com/?page_id=365

dzywicki

Thank you Saudade. I saw it was from RHD, but the circuit looked like it would be close enough. I will get the correct FSM and go from there.

dzywicki

I did prototype install of the push button starter today. Works great. Was also able to verify continuity between the ignition switch start wire and the starter relay so either the ignition switch or actuator pin piece. Both should be here Monday. I bought switch from Amazon and it fits in where the cigarette lighter normally is. Should be a pretty clean install and will probably leave it even after I replace the other stuff.

dzywicki

Got it all wired up and it came out pretty nice (I think). Tied into the wiring at the ignition switch so didn't have to run wire through the firewall. Actuator pin part should be here Monday or Tuesday. I did have to use a Dremel tool and take some of the plastic off of the back where the cigarette lighter is so the button showed some threads.

dzywicki

The push button start was giving me problems already so I dove in an replaced the actuator pin mechanism and the ignition switch. Not a difficult job, just fiddly and nota lot of space to work in. Remove the lower dash cover and metal support plate. Remove the steering column cover. Get your tamper proof torx bits, remove the one screw holding the actual ignition switch in place. Put the key in run position and push the button to pull the key lock cylinder out. Remove the shift lock mechanism. Two tamper proof torx on the bottom holding the actuator cover and then it all comes out. There is a spring between the pin actuator and the lower cover you have to watch out for. Repalcement is the opposite of removal. Took me ~45 minutes but that was because I took a few breaks from the humidity and being upside down.

View from underneath

New ignition switch

Broken metal on the old one.